Microsoft Edge plus Chromium is official
Ultimately, we want to make the web experience better for many different audiences. People using Microsoft Edge (and potentially other browsers) will experience improved compatibility with all web sites, while getting the best-possible battery life and hardware integration on all kinds of Windows devices. Web developers will have a less-fragmented web platform to test their sites against, ensuring that there are fewer problems and increased satisfaction for users of their sites; and because well continue to provide the Microsoft Edge service-driven understanding of legacy IE-only sites, Corporate IT will have improved compatibility for both old and new web apps in the browser that comes with Windows.
Source: Microsoft Edge: Making the web better through more open source collaboration - Windows Experience Blog - Windows Experience Blog
Unimaginable not that long ago.